Hot-pressed nano-composite polymer electrolytes: (1-<i style="">x</i>) [70PEO:30KBrO₃]:<i style="">x</i>SiO₂

Abstract

The electrical and electrochemical properties of PEO-based hot-pressed nano-composite polymer electrolyte (NCPE) membranes: (1-<i>x</i>) [70PEO:30KBrO₃]:<i>x</i>SiO₂, where <i>x</i> = 0-20 wt. (%), have been studied. NCPE membranes have been casted using a novel hot-press technique in place of the traditional solution cast method. The conventional Solid Polymer Electrolyte (SPE) composition: (70PEO: 30KBrO₃), identified as the highest conducting film at room temperature, has been used as I^st-phase host matrix and nano-size (~8 nm) particles of SiO₂ as II^nd-phase dispersoid. As a consequence of dispersal of SiO₂in SPE host, a conductivity enhancement of an order of magnitude was achieved in NCPE film: [95(70PEO:30KBrO₃):5SiO₂]. This composition has been referred to as Optimum Conducting Composition (OCC). Materials characterization has been done with the help of SEM and DSC techniques. The ion transport behaviour in NCPE membranes have been discussed on the basis of conductivity (σ), mobility (µ), mobile ion concentration (n) and ionic transference number (<i style="">t</i>_ion) studies. The temperature dependent conductivity studies have also been done to compute the activation energy (<i style="">E</i>_a) values by least square linear fitting of ‘logσ-1/<i style="">T</i>’ Arrhenius plots. Thin film solid-state polymeric batteries were fabricated using NCPE OCC as electrolyte and the cell-potential discharge characteristics were studied under different load conditions.